"Although the TAC-PAC® case is designed for many different calibers of ammunition, due to differences in manufacturing, slight variations of size in the same caliber ammunition can occur. This can alter the way the ammunition fits in any fixed-size ammunition box, including the TAC-PAC® case. While the stability and security of ammunition encased in a TAC-PAC® box should not be compromised, different brands of ammunition may not fit as tightly in the case. Please contact TAC PAC for questions."